Ionic Liquids with Multi‐Active Sites Synergistically Catalyzed Metal‐Free Transformation of Alcohols Using Dimethyl Carbonate as an Environmental Solvent
Pyridine-based ionicliquids with multiple activesitessynergisticallycatalyzed C3 substitution of 4-hydroxycoumarin with alcohols in dimethylcarbonate was demonstrated. The system was efficient, economic and environmental and successfully applied for the synthesis of coumatetralyl as commercial rodenticide. And a mechanism involving a SN1 pathway, synergistically promoted effect of hydrogen bonding
HFIP Promoted C3 Alkylation of Lawsone and 4-Hydroxycoumarin with Alcohols by Dehydrative Cross-Coupling
作者:Yixin Chen、Yurong Wang、Rong Zhong、Jinshan Li
DOI:10.1021/acs.joc.0c01207
日期:2020.8.21
An environmentally benign system for the direct alkylation of lawsones and 4-hydroxycoumarins with alcohols in 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) is reported. The reaction proceeded smoothly via a dehydrative cross-coupling process by utilizing the unique properties of HFIP. A variety of alkylated products and subsequent one-pot cyclized products (pyranonaphthoquinones and pyranocoumarins) could be obtained in 40-93% yields.